Check for worms or face potential losses, warns St David’s Poultry
9th November 2015
Free-range poultry farmers should check their flocks for signs of intestinal worms to reduce the risk of egg losses and other diseases, according to Richard Turner from St David’s Poultry Team.
Worms are a common and often overlooked reason for poor health and production in free-range flocks, particularly on farms that have been operating for a number of years. Worms can damage the bird’s gut, which in turn allows infection and bacteria to pass through the gut wall, leading to other health problems. The damage to the gut also causes poor nutrient uptake, so the birds eat more than normal, leading to poor feed conversion ratios.
The damaged intestine tends to lead to rapid food passage, and the movement of non-digested food to the lower intestine results in an imbalanced bacterial population, often causing frothy droppings. The bacterial population in both birds and humans represents almost 90% of the total cells in the body, so looking after the normal bacteria is very important. Secondary infections such as egg peritonitis, bacterial infections and brachyspira can also be associated with worms. In addition, producers can see increased cannibalism through vent pecking, and in the case of high worm infestations, blockages to the intestine can result in mortality. There are three main types of worms to look out for:
- Roundworms (Ascaridia Galli), which are white and up to 50mm long.
- Hairworms (Capillaria) are small and barely visible to the naked eye. These worms can cause severe damage to the intestine even in small numbers.
- Caecal worms (Hetarakis Gallinarum) live in the caeca of the gut and don’t cause any particular problem on their own. However, they carry another parasite; Histomonas, which in turn can cause Blackhead, and leads to increased mortality in a flock.
To test for worms producers should either examine dead or culled birds’ intestines for evidence of worms, or send faecal samples to be examined for worm eggs, which give an indication of the level of infestation.
It is very important to take a range of faecal samples so that the results are representative of the flock. It’s also important that the samples are well mixed in the laboratory to obtain an accurate result.
The life cycle of worms is measured in weeks not months, but worm eggs can survive for a long time on pasture so producers should test their flock monthly if routine treatment is not carried out. As the bird gets older resistance develops, but it is not uncommon to see worms in adult birds, and the treatments available don’t treat all stages of the life cycle. If worms are present there are two means of treatment using the active ingredient Flubendazole; as a feed additive or in-water treatment. Water-based products can be cheaper and allow more flexibility to treat without worrying about feed deliveries, although feed additives are more straightforward. There are slight differences between products so it is important to take veterinary advice on which is most appropriate for your flock and situation.
Routine worming can provide the best results as often once worms are identified as a problem the birds are already suffering from loss of production. However, it’s important to follow veterinary advice to reduce the risk of anthelmintic resistance building up. Worms are seldom seen but always present, and carrying out regular faecal egg counts is inexpensive when compared to the loss of egg production.
- For more information regarding worm egg count testing or to order worming kits contact St David’s Poultry Team on 01392 872932.